1. Evolution of species

Species: A basic taxonomy category. Population of individuals bearing distinctive genes and gene frequencies, separated from other species by biological barriers preventing gene exchange.

Evolution: Genetic changes in populations of organisms through time that lead to differences among them.

Selection: A composite of all the forces that cause differential survival and differential reproduction among genetic variants.

Phylogeny: The evolutionary history of a species or group of species in terms of their derivations and relationships.


  1. Life on Earth
  2. The tree of life
  3. Entrez
  4. Phylogeny in a nutshell